27 January 2009

Mushrooms for Breakfast, Mushrooms for Lunch, Mushrooms for . . .

Gilbert's Potoroo, named for the English naturalist John Gilbert, is perhaps the most endangered marsupial in Australia. Known as the Ngil-gyte by local aboriginals, it is a small marsupial rat-kangaroo, with soft fur, bulging eyes, and a tail almost as long as its 30cm body. If you know what bandicoots and wallabies look like, a potoroo is somewhere in the middle. Fewer than 50 wild individuals are restricted to two tiny areas on the southern coast of Western Australia.

These shy nocturnal creatures are an oddity in the mammal world, in that they are fungivores. That is, 90% of their diet consists of truffles, the fruiting body of underground fungi. The spores of over 40 types of truffle have been found in their dung! The rest of their diet consists of small insects and small fleshy fruit.

It was first discovered around 1840 in southwest Australia, when John Gilbert wrote that large numbers were procured by aboriginals for food in the space of a few hours. By 1870, it was believed extinct. It wasn't until more than 120 years later, in 1994 that Gilbert's Potoroo was discovered, still alive in Two Peoples Bay Nature Reserve. Since then, a captive breeding population has been established in the same area, and another wild population has been established on nearby Bald Island. Currently, plans are underway to establish a third wild population at Waychinicup National Park.

The establishment of these distinct populations is crucial to increasing Gilbert's Potoroo's chances of survival. Threatened by wildfire (they live in dense, highly flammable vegetation that has remained unburnt for 50 or more years), introduced predators (feral foxes and cats), and changes to their habitat, their tiny population is at constant risk of extinction by a single catastrophic event. That is, a single wildfire could wipe out the majority of the population.

Research continues to learn more about the needs of Gilbert's Potoroo, as well as to help conservationists increase the breeding success of the captive population.